No abstract

Experimental Dermatology. 2020;29:535-538. | 535 wileyonlinelibrary.com/journal/exd 1 | BACKG ROU N D Vitiligo is a pigmentary disease characterized by epidermal melanocyte loss resulting in white patches on the affected skin areas.Autoimmunity has been well accepted as a possible cause for vitiligo; in addition, evidence of a polygenic transmission of common, low-effect-size risk alleles was found within multiplex-vitiligo-affected families, as well as high heritability (h 2 ~ 0.75), [1] suggesting an important genetic basis controlling susceptibility to the disease. Recently, genome-wide association studies (GWAS) have identified 50 loci, with each locus contributing a small amount to the overall vitiligo heritability. [1] Several of these genes encode for molecules involved in regulation of immune response, such as MHC genes, PTPN22, LPP, IL2RA and UBASH3A. Besides, candidate gene studies have identified association signals often concentrated among individuals or nuclear families presenting autoimmune comorbidities. [2,3] These findings suggest the existence of a shared genetic mechanism between vitiligo and other autoimmune disorders. | QUE S TIONS ADDRE SS EDHere, we investigated genes previously related to autoimmune diseases for association with vitiligo, using two independent population samples of different designs. AbstractThe aetiology of vitiligo has not been fully elucidated, and several hypotheses have been investigated; among them, the most explored assumes an autoimmune basis for the disease. Supporting this hypothesis is the frequent co-occurrence of autoimmune diseases with vitiligo. In addition, various genetic loci associated with vitiligo harbour key immune response genes. Our general hypothesis is that autoimmunity-associated genes participate in the control of vitiligo susceptibility. To investigate this hypothesis, we tested for association between vitiligo and genes CYP27B1, REL, TNFAIP3 and IL2/IL21, all previously related to autoimmune diseases associated with vitiligo. The study was performed using two independent population samples: a family-based discovery set (211 trios) and a replication set (131 cases/119 controls). Statistically significant association with vitiligo was detected between markers of the REL and IL2 gene in the family-based sample. Both association signals were concentrated among patients displaying autoimmune comorbidity and non-segmental vitiligo. Evidence for validation was detected for IL2 marker. Our findings suggest REL and IL2 as new vitiligo susceptibility genes and reinforce the hypothesis of a shared genetic mechanism controlling vitiligo and other autoimmune diseases. K E Y W O R D Sautoimmunity, genetics, IL2, REL, vitiligo

No abstract

Background: Ghrelin is a hormone that exhibits effects in a lot of biologic processes, such as food intake regulation, gastrointestinal motility and carbohydrate metabolism. Ghrelin is encoded by human preproghrelin gene (GHRL), reported with four exons. However, experiments suggested a new molecular structure for this gene. Objective: This study aims to clarify by a simple representation GHRL and its products, showing the variants described for this gene up to this moment. Methods: The GHRL sequence for molecular comparisons was obtained from GeneBank. The dbSNP was used to search variants and the PubMed, Scielo and Science Direct databases to investigate related studies. Results: The new molecular structure of GHRL includes a new exon 0 and an extended exon 1, located in the originally identified region of intron 1. Examples of GHRL products are signal, ghrelin and obestatin peptides and these molecules exhibit different effects on the organism. Thus, polymorphisms in these gene regions have been associated with a vast number of clinical effects, including metabolic disorders. We identified 11 genetic variations in the region of the GHRL which encodes for the signal peptide and 23 polymorphisms in the ghrelin coding region. One of them, rs34911341, has been associated with some disorders such as diabetes, hypertension and obesity. Conclusion: In this scientific article we turned GHRL a little bit more informative for readers. Furthermore we highlighted the current reported GHRL genetic variations associated to signal and ghrelin peptides, but only the variant rs34911341 has been associated with metabolic disorders.

No abstract